The FCIA has hosted two webcasts on protocol analysis, Protocol Analysis for High-Speed Fibre Channel Fabrics, which covered the basics on protocol analysis followed by a more advanced session, Protocol Analysis 201 for High-Speed Fibre Channel Fabrics. If you missed one, or want to watch them again, they are both available on demand.

The recent 201 session provided a deeper dive into how to interpret the output and results from the protocol analyzers. Attendees had some good questions during the live event that our expert presenters, Yamini Shastry and David Rodgers have answered here.

Q: What are the maximum frame and the maximum payload sizes that are currently supported by your analyzers?

A: Viavi’s Xgig analyzer supports a Frame/payload size of 2148 bytes for FC which is the maximum size defined by the specification. The Teledyne LeCroy SierraNet analyzers also support the maximum FC frame payload size

Q: Can you setup triggers to determine a throughput drop?

A: Viavi analyzers currently do not support triggers on throughput drop. It is tricky to use visual triggers when the throughput drop isn’t significant. The user may have to filter out the problem device and then stop on visual trigger or use external triggers. The Teledyne LeCroy SierraNet tools have an event timer utility. When configured for throughput drop, the timer would be set to look for the corresponding data frame, RRDY, or other indicator of exchange. If the value being observed did not transit the link under test within the programmed timeframe, the analyzer would be triggered to capture the data on the link.

Q: Do the jammer products support changing Op Code commands?

A: Both the Viavi Xgig and Teledyne LeCroy SierraNet support jamming SPC, SBC or other SCSI commands. Additionally, as the specifications for NVMe over Fabrics evolve, the jammer tools are capable of injecting errors here too.

Q: Do the Jammer products support jamming the PHY Layer interactions?

A: The Teledyne LeCroy tools are useful in viewing and jamming the link layer transactions for testing link recovery. The increase in serial communications speeds has the engineering team spending more time ensuring the basic link operations are functioning as expected, so more direct testing of PHY and link layer protocols appears to be on the horizon.

We hope you will continue to keep up with the FCIA’s educational webcasts. Our next one will be in on Fibre Channel Zoning Basics on June 27, 2019. Register here to save your spot.